Drill collar float valve for well drilling strings



May 17, 1938. R'. c. BAK 1 2,117,533

DRILL COLLAR FLOAT VALVE FOR WELL DRILLING" STRINGS Filed Oct. 10, 1936 INVENTOR.

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ATTORNEY Patented May 17, 1938 UNITED STATES PATENT- oFFlcE I DRILLING STRINGS Reuben C. Balier, Coalinga, (lalif., assignor to BakcrOil'Tools, Inc., Huntington Park, Calif.,' acorporation of California "Applicatioii October l0, 1936, Serial No. 105,039

1 Claim." (01. 137--69) This invention relates to well drilling equipment and particularly pertainsto a drill collar float valve structure.

It is the principal object of my present inven- 5 tion to provide an improved float valve mecha: nism which may be incorporated in a drill collar of a well drilling string.

In practicing my invention, I provide a drill collar having a straight bore formed therein. A

m hollow cylindrical valve body is provided and which reciprocably fits said bore, and which is provided with suitable sealing means preventing the flow of fluid between the said body and said bore. The body is formed with a valve seat in- ;5 termediate its ends and is fitted with a springpressed valve for cooperation with said seat to enable fluid to be pumped downwardly through the drill collar, but to prevent the flow of fluid upwardly therethrough. The valve body is retained in the bore between the pin of the bit fitting in the lower end of the collar and between a shoulder formed at the upper end of the bore in the collar.

One form which the invention may assume is O exemplified in the following description and illustrated by way of example in the accompanying drawing, in which:

Fig. 1 is a central vertical sectional view through a drill collar float valve structure embodying the preferred form of my invention.

Fig. 2 is a perspective view of the valve body assembly.

Fig. 3 is a transverse sectional View taken on line IIIIII of Fig. 1.

35 Referring more particularly to the accompanying drawing, IE! indicates a well drilling string, H the drill collar, which connects the well drilling string It to the bit I2. The upper end of the drill collar I I is formed with a box I4 adapted to 40 be threadedly engaged with the pin of a tool joint I5 directly thereabove, and the lower end of the drill collar II is formed with a box IE to receive the pin ll of the bit I2. The drill collar member II is formed with a straight bore I8 45 which commences at the inner end of the box It and extends to the box I4. The diameter of the bore is less than the smallest diameter of the thread formed in the box I6.

Adapted to be reciprocably received in the bore 50 I8 is a valve body 29. This valve body is formed at its upper end with a cylinder 2|, the exterior diameter of which is just slightly less than the bore I8, and which is fitted with opposed cup rings 22 to prevent the passage of fluid in 55 either direction between the exterior of the cyl- DRILL comm FLO-AT VALVE I Fort WELL inder 2| and the bore I8. At its lower endthis cylinder 2I is formed with an interior valve seat 23 withwhich anupwardly seating valve 24 cooperates, At a spaced distance from the cylinder H the valve body is formed with a second cyline drical section 25 connected by integral and diametrically opposed legs 26 with the cylinder 2|. From the lower end of the portion 25 of the valve body project opposed legs 21.

Within the cylindrical portion 25 of the valve body is a spider 28 having a bore 29 formed longitudinally therethrough and concentrically with respect to the cylindrical portion 25. The upper end of this bore is counterbored as at 30 to receive the lower end of the fixed valve stem 3|. A cap screw 32 is provided which projects upwardly through the bore 29 in the spider 28 and is threaded into the lower end of the valve stem 3| to secure the same in position. The valve member 24 is hollow and is provided interiorly with radial ribs 24a which slidably engage the valve stem 3| and guide the valve member 24 in its vertical movement. A spring 33 is provided which tends to constantly maintain the valve member 24 seated on its seat 23. At the sides of the cylindrical portion 25 of the valve body are springs 34 for holding weight of assembly until bit pin is screwed in box I6.

It should be said that the overall distance between the ends cf the legs 21 and the upper end of the cylinder 2I is less than the distance between the upper end of the pin ll of the bit and the lower end of the pin of the tool joint I5. Ordinarily this distance is considerable in order to permit recuts of the threads in the box I6. Obviously, each time these threads are recut, the pin I! of the bit I2 will project further upwardly into the drill collar. Consequently, by providing the valve body of an overall length less than the distance between the upper end of the pin I1 and the lower end of the pin of the tool joint I5, the valve body will fit and function properly in the drill collar regardless of recutting.

In operation of the device the valve body 20 is placed in the bore of the drill collar and the latter is then made up on the bit I2. The remainder of the drilling string is then made up on the drill collar. When the bit is lowered into the well bore, the force of the fiuid in the bore will immediately attempt to pass through the cylinder 2|, but due to the fact that this is closed by the valve 24 the fluid pressure will cause the entire valve body to move upwardly in the bore I8 until the upper end of the valve body engages the pin of the joint I5, and thereafter a floating action will result to float the drill string into the hole.

When the circulating fluid is pumped downwardly through the drill string, it will impinge against the valve 24 and unseat the same and at the same time cause the entire valve body to lower until the lower ends of the legs 2! engage the pin l1, and thereby the drilling fluid may be pumped downwardly through the valve body. It will be seen, of course, that the opposed rubber packing or sealing rings 22 will prevent the passage of fluid between the exterior of the cylinder 2| and the bore I8.

When the bit is removed from the hole and disconnected from the drill collar, the entire valve assembly may be merely pulled from the bore, and if the valve, or seat, or its stem, needs repair, it is only necessary toremove the one cap screw 32 and insert a pin or other tool through the openings 30a and remove theentire valve stem and valve from the valve body through the spaces between the legs 26.

From the foregoing it is obvious that I have provided a very simple and very efficient drill collar float for use in connection with well drilling strings, and while I have shown the preferred form of my invention, it is to be understood that various changes may be made in its construction by those skilled in the art without departing from the spirit of the invention as defined in the appended claim.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

In combination, a drill collar having a straight bore formed therein, a valve body reciprocably mounted in said bore, said body including a hollow cylindrical portion, sealing means on the exterior of the cylindrical portion to prevent passage of fluid between it and the bore, a valve seat on the cylinder circumscribing its interior, said body including a spider rigidly suspended from said cylindrical portion, an upwardly projecting valve stem rigidly held in coaxial relation to said cylinder by said spider, an upwardly seating hollow valve member fitting over the upper end of said stem and axially movable with respect thereto, and spring means constantly tending to seat said valve on said seat.

REUBEN C. BAKER. 

